diff --git a/thresh/src/main/java/monasca/thresh/domain/service/AlarmDAO.java b/thresh/src/main/java/monasca/thresh/domain/service/AlarmDAO.java
index ce844fd..b3c6b5c 100644
--- a/thresh/src/main/java/monasca/thresh/domain/service/AlarmDAO.java
+++ b/thresh/src/main/java/monasca/thresh/domain/service/AlarmDAO.java
@@ -48,4 +48,7 @@ public interface AlarmDAO {
 
   /** Update SubAlarms when AlarmDefinition changes */
   int updateSubAlarmExpressions(final String alarmSubExpressionId, AlarmSubExpression alarmSubExpression);
+
+  /** Deletes all alarms for the given AlarmDefinition */
+  void deleteByDefinitionId(String alarmDefinitionId);
 }
diff --git a/thresh/src/main/java/monasca/thresh/infrastructure/persistence/AlarmDAOImpl.java b/thresh/src/main/java/monasca/thresh/infrastructure/persistence/AlarmDAOImpl.java
index 6ad36f5..c78d0f3 100644
--- a/thresh/src/main/java/monasca/thresh/infrastructure/persistence/AlarmDAOImpl.java
+++ b/thresh/src/main/java/monasca/thresh/infrastructure/persistence/AlarmDAOImpl.java
@@ -294,6 +294,13 @@ public class AlarmDAOImpl implements AlarmDAO {
     }
   }
 
+  @Override
+  public void deleteByDefinitionId(String alarmDefinitionId){
+    try (Handle h = db.open()) {
+      h.execute("delete from alarm where alarm_definition_id = :id", alarmDefinitionId);
+    }
+  }
+
   private MetricDefinition createMetricDefinitionFromRow(final Map<String, Object> row) {
     final Map<String, String> dimensionMap = new HashMap<>();
     final String dimensions = getString(row, "dimensions");
diff --git a/thresh/src/main/java/monasca/thresh/infrastructure/thresholding/AlarmCreationBolt.java b/thresh/src/main/java/monasca/thresh/infrastructure/thresholding/AlarmCreationBolt.java
index 0bf1816..b570438 100644
--- a/thresh/src/main/java/monasca/thresh/infrastructure/thresholding/AlarmCreationBolt.java
+++ b/thresh/src/main/java/monasca/thresh/infrastructure/thresholding/AlarmCreationBolt.java
@@ -198,6 +198,7 @@ public class AlarmCreationBolt extends BaseRichBolt {
     }
     alarmCache.remove(alarmDefinitionId);
     alarmDefinitionCache.remove(alarmDefinitionId);
+    alarmDAO.deleteByDefinitionId(alarmDefinitionId);
   }
 
   protected void handleNewMetricDefinition(
diff --git a/thresh/src/main/java/monasca/thresh/infrastructure/thresholding/AlarmThresholdingBolt.java b/thresh/src/main/java/monasca/thresh/infrastructure/thresholding/AlarmThresholdingBolt.java
index 2948ae9..8730fe8 100644
--- a/thresh/src/main/java/monasca/thresh/infrastructure/thresholding/AlarmThresholdingBolt.java
+++ b/thresh/src/main/java/monasca/thresh/infrastructure/thresholding/AlarmThresholdingBolt.java
@@ -69,7 +69,7 @@ public class AlarmThresholdingBolt extends BaseRichBolt {
   private transient Logger logger;
   private DataSourceFactory dbConfig;
   private KafkaProducerConfiguration producerConfiguration;
-  final Map<String, Alarm> alarms = new HashMap<String, Alarm>();
+  final Map<String, Alarm> alarms = new HashMap<>();
   final Map<String, AlarmDefinition> alarmDefinitions = new HashMap<>();
   private transient AlarmDAO alarmDAO;
   private transient AlarmDefinitionDAO alarmDefinitionDAO;
@@ -217,8 +217,16 @@ public class AlarmThresholdingBolt extends BaseRichBolt {
   }
 
   private void changeAlarmState(Alarm alarm, AlarmState initialState, String stateChangeReason) {
-    alarmDAO.updateState(alarm.getId(), alarm.getState());
     final AlarmDefinition alarmDefinition = alarmDefinitions.get(alarm.getAlarmDefinitionId());
+    // If the Alarm Definition id does not exist, ignore updating this alarm
+    if (alarmDefinition == null) {
+      logger.warn("Failed to locate alarm definition for id {},"
+                  + " ignoring state update to alarm with id {}",
+                  alarm.getAlarmDefinitionId(),
+                  alarm.getId());
+      return;
+    }
+    alarmDAO.updateState(alarm.getId(), alarm.getState());
     final List<MetricDefinition> alarmedMetrics = new ArrayList<>(alarm.getAlarmedMetrics().size());
     for (final MetricDefinitionAndTenantId mdtid : alarm.getAlarmedMetrics()) {
       alarmedMetrics.add(mdtid.metricDefinition);
diff --git a/thresh/src/test/java/monasca/thresh/ThresholdingEngineAlarmTest.java b/thresh/src/test/java/monasca/thresh/ThresholdingEngineAlarmTest.java
index 28d0b8b..4a84b23 100644
--- a/thresh/src/test/java/monasca/thresh/ThresholdingEngineAlarmTest.java
+++ b/thresh/src/test/java/monasca/thresh/ThresholdingEngineAlarmTest.java
@@ -445,5 +445,8 @@ public class ThresholdingEngineAlarmTest extends TopologyTestCase {
       }
       return false;
     }
+
+    @Override
+    public void deleteByDefinitionId(String alarmDefinitionId) {}
   }
 }